Flexures are used in systems where there is motion between one portion of the system and another. In order to create the motion, there must be a force. In some cases, this force comes from an actuator or motor that provides a controlled force that creates movement. In such systems, flexures are usually used to connect the moving portion of the system to the stationary portion of the system. The flexure must be designed so that its stiffness is low enough so as to not impede motion in the desired direction. In particular, to reduce the force requirements on the actuator or motor, the stiffness of the flexure must be as low as possible in the movement direction.
During design of a low stiffness flexure, the cross section of the flexure is usually designed to be as small as possible along the direction of bending, and the length is made as long as possible. However, there are limits on the design of the dimensions of conventional flexures. In some systems, these dimensions are limited by fabrication limits. For example, stamped metal flexures cannot be made too thin or too long without affecting handling and manufacturability. In other systems, the desire to make the cross section of the flexure as small as possible conflicts with other system requirements. For example, if the flexure is designed to carry electricity, making the flexure cross section very small increases the resistance, which wastes power and can lead to failure if enough current flows through the flexure.